This project consists of three related lines of research evaluating 1) the relationship between plasma beta-endorphin levels and pain; 2) the role of exogeneous epinephrine administrered with local anesthetics on plasma levels of epinephrine and cardiovascular performance; and 3) the clinical efficacy of drugs given to modify the stress of minor surgery. The major effort during the past year has been to examine the relationsip between modifying perceived levels of pain and anxiety caused by oral surgery and concommitant levels of beta-endorphin. Results to date indicate that both diazepam and fentanyl suppress stress-induced release of beta-endorphin while naloxone increases release and produces hyperalgesia during oral surgery. Adminisration of human corticotropin releasing factor resulted in a signficant elevation of plasma beta-endorphin which resulted in less postoperative pain in comparison to placebo. These data suggest a relationship between plamsa levels of beta-endorphin and pain which may be a logical avenue for further research to design drugs which activate the endogeneous pain inhibitory system without the liabilities of present agents.